The present invention relates to a slack correction mechanism used with an apparatus in which a distal end member mounted on a pulley is put in operation by pulling or letting out a wire wound around the pulley for the purpose of correcting slack in the wire as well as a manipulator and a manipulator system.
FIGS. 16A, 16B and 16C is a schematic view of one example of one typical prior art manipulator.
So far there has been a manipulator used in which a wire 130 is wound on one side around a driving pulley 140 and on the other side around a driven pulley 120 for power transmission, as shown in FIG. 16A.
When the driving pulley 140 is rotated by an operator (not shown) from a neutral state of FIG. 16A in a direction indicated by an action arrow A1, the wire 130 tends to move in a direction indicated by an action arrow B in association with the rotation of the driving pulley 140 in the direction indicated by the action arrow A1. Because the necessary load is applied to the driven pulley 120 when it starts to rotate, however, the driven pulley 120 does not rotate even upon rotation of the driving pulley 140. For this reason, there is an elongation 131 of the wire 130 pulled by the driving pulley 140, and there is slack 132 in the wire 130 let out by the driving pulley 140, as shown in FIG. 16B.
When the driving pulley 140 is then reversed in a direction indicated by an action arrow A2 as shown typically in FIG. 16C, the pulling force is not transmitted to the driven pulley 120 until the dynamic slack 132 in the wire 130, shown in FIG. 16B, is removed, with the result that a distal-end member 121 attached to the driven pulley 120 is unlikely to go into operation even with the operation of the driving pulley 140, as shown in FIG. 16C.
Japanese Patent No. 4145464 discloses the technology of pulling the slack in the wire by means of a spring for removal of such slack 132 as shown in FIG. 16B thereby reducing operational delay shown in FIG. 16C.